Flagellar Sigma Factor FliA Is Required for Dickeya dadantii Virulence

• Published in: Molecular plant-microbe interactions Vol. 21; no. 11; pp. 1431 - 1442
• Main Authors: Jahn, Courtney E, Willis, David K, Charkowski, Amy O
• Format: Journal Article
• Language: English
• Published: St Paul, MN APS Press 01-11-2008; The American Phytopathological Society
• Subjects: ambient temperature; Amino Acid Sequence; bacterial motility; Bacterial plant pathogens; bacterial proteins; Bacterial Proteins - genetics; Bacterial Proteins - physiology; Biological and medical sciences; culture media; Dickeya chrysanthemi - genetics; Dickeya chrysanthemi - pathogenicity; Enterobacteriaceae; Erwinia chrysanthemi; flagellin; flagellum; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Regulation, Bacterial; genome; microbial genetics; Models, Genetic; Molecular Sequence Data; mutation; Nicotiana - microbiology; Nicotiana benthamiana; nucleotide sequences; Pectobacterium chrysanthemi; phenotype; Phytopathology. Animal pests. Plant and forest protection; pleiotropy; protein secretion; Sequence Homology, Amino Acid; Sigma Factor - genetics; Sigma Factor - physiology; Temperature; virulence; Virulence - genetics; Disease development; Polysaccharide-lyases; Nicotiana benthamiana; Temperature; Plant pathogen; Virulence; Flagellum; Flagellin; Lyases; Gene; Dicotyledones; Angiospermae; Bacteria; Solanaceae; Enterobacteriaceae; Pectate lyase; Nucleotide sequence; Enzyme; Secretion; Adhesion; Infection; Growing medium; Phenotype; Erwinia chrysanthemi; Bacteriosis; Biofilm; Initiation factor σ; Spermatophyta; Mutation; Experimental plant; Carbon-oxygen lyases
• ISSN: 0894-0282; 1943-7706
• DOI: 10.1094/mpmi-21-11-1431

The genome sequence of the Enterobacteriaceae phytopathogen Dickeya dadantii (formerly Erwinia chrysanthemi) revealed homologs of genes required for a complete flagellar secretion system and one flagellin gene. We found that D. dadantii was able to swim and swarm but that ability to swarm was dependent upon both growth media and temperature. Mutation of the D. dadantii fliA gene was pleiotropic, with the alternate sigma factor required for flagella production and development of disease symptoms but not bacterial growth in Nicotiana benthamiana leaves. The flagellar sigma factor was also required for multiple bacterial phenotypes, including biofilm formation in culture, bacterial adherence to plant tissue, and full expression of pectate lyase activity (but not cellulase or protease activity). Surprisingly, mutation of fliA resulted in the increased expression of avrL (a gene of unknown function in D. dadantii) and two pectate lyase gene homologs, pelX and ABF-0019391. Because FliA is a key contributor to virulence in D. dadantii, it is a new target for disease control.